From 2beeb454a448c2679102fc398183ec351d5c707c Mon Sep 17 00:00:00 2001
From: Anthony Scemama <scemama@irsamc.ups-tlse.fr>
Date: Sat, 15 Jul 2017 01:02:13 +0200
Subject: [PATCH] Solved bug for large calculations

---
 src/Determinants/slater_rules.irp.f | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/Determinants/slater_rules.irp.f b/src/Determinants/slater_rules.irp.f
index 80dbbad4..e3f5c0b1 100644
--- a/src/Determinants/slater_rules.irp.f
+++ b/src/Determinants/slater_rules.irp.f
@@ -43,10 +43,12 @@ subroutine get_excitation_degree(key1,key2,degree,Nint)
       degree = sum(popcnt(xorvec(1:8)))
 
     case default
-      do l=1,ishft(Nint,1)
+      integer :: lmax
+      lmax = ishft(Nint,1)
+      do l=1,lmax
         xorvec(l) = xor( key1(l), key2(l))
       enddo
-      degree = sum(popcnt(xorvec(1:l)))
+      degree = sum(popcnt(xorvec(1:lmax)))
   
   end select
 
@@ -1503,14 +1505,16 @@ subroutine get_excitation_degree_vector_double_alpha_beta(key1,key2,degree,Nint,
     !DIR$ LOOP COUNT (1000)
     do i=1,sze
       d = 0
+      degree_alpha = 0
+      degree_beta  = 0
       !DIR$ LOOP COUNT MIN(4)
       do m=1,Nint
         d = d + popcnt(xor( key1(m,1,i), key2(m,1)))                 &
               + popcnt(xor( key1(m,2,i), key2(m,2)))
         key_tmp(m,1) = xor(key1(m,1,i),key2(m,1))
         key_tmp(m,2) = xor(key1(m,2,i),key2(m,2))
-        degree_alpha = popcnt(key_tmp(m,1)) 
-        degree_beta  = popcnt(key_tmp(m,2)) 
+        degree_alpha += popcnt(key_tmp(m,1)) 
+        degree_beta  += popcnt(key_tmp(m,2)) 
       enddo
       if(degree_alpha .gt.3 .or. degree_beta .gt.3 )cycle !! no double excitations of same spin
         degree(l) = ishft(d,-1)
@@ -1661,12 +1665,13 @@ subroutine get_excitation_degree_vector_mono_or_exchange_verbose(key1,key2,degre
     do i=1,sze
       d = 0
       exchange_1 = 0
+      exchange_2 = 0
       !DIR$ LOOP COUNT MIN(4)
       do m=1,Nint
         d = d + popcnt(xor( key1(m,1,i), key2(m,1)))                 &
               + popcnt(xor( key1(m,2,i), key2(m,2)))
-        exchange_1 = popcnt(xor(iand(key1(m,1,i),key1(m,2,i)),iand(key2(m,1),key2(m,2))))  
-        exchange_2 = popcnt(iand(xor(key1(m,1,i),key2(m,1)),xor(key1(m,2,i),key2(m,2))))   
+        exchange_1 += popcnt(xor(iand(key1(m,1,i),key1(m,2,i)),iand(key2(m,1),key2(m,2))))  
+        exchange_2 += popcnt(iand(xor(key1(m,1,i),key2(m,1)),xor(key1(m,2,i),key2(m,2))))   
       enddo
       if (d > 4)cycle
       if (d ==4)then  
@@ -2225,7 +2230,7 @@ subroutine get_excitation_degree_spin(key1,key2,degree,Nint)
       degree = sum(popcnt(xorvec(1:4)))
 
     case default
-      do l=1,N_int
+      do l=1,Nint
         xorvec(l) = xor( key1(l), key2(l))
       enddo
       degree = sum(popcnt(xorvec(1:Nint)))